A multi-touch capacitive touchscreen includes an on-cell touchscreen and an in-cell touchscreen. A node that is used by the on-cell touchscreen and the in-cell touchscreen to implement touch control may be a bonding pad. A large quantity of nodes are used on the on-cell screen, for example, a 7-inch liquid crystal display (LCD) with a resolution of 600×1024 requires 15×26 nodes, that is, 390 nodes. Due to a complex process, a larger quantity of nodes increases the probability of abnormal nodes. For example, if a node is in poor contact, an impedance of the node becomes larger, and further, a capacitance of the node cannot be fully charged. As a result, a capacitance value of the node frequently fluctuates.
Generally, a touchscreen of a touchscreen terminal detects a capacitance value of each node in the touchscreen. When the touchscreen receives a touch operation of a user, a capacitance value of a corresponding node within coverage of a touch area varies. When a variation value of the capacitance value exceeds a threshold, the touchscreen reports the node to an application processor of the touchscreen terminal, then the application processor determines the touch operation according to coordinates of the node and a report time, and finally the screen terminal executes a function corresponding to the touch operation, such as unlocking the screen.
Because the capacitance value of the abnormal node fluctuates frequently, the touchscreen detects that the variation of the capacitance value of the abnormal node exceeds the threshold, and then reports the node to the application processor. Actually, the touchscreen does not receive any touch operation. Instead, due to a spontaneous variation of the capacitance value of the abnormal node, the touchscreen has a poor fault tolerance capability.